Fat: The Big Picture

The network of genes required for early steps in the development of brown fat cells has been identified in new research to be published in the June issue of Nature Cell Biology, further substantiating the link between insulin signalling and control of fat cells. The complete picture of the network should provide an important blueprint for future clinical and therapeutic approaches to diabetes and obesity.

Mice defective in different aspects of insulin signalling -- a process known to regulate fat-cell differentiation -- produce precursors at varying stages of fat-cell differentiation. These precursors were used to identify the global pattern of gene expression as cells develop into fully defined brown fat cells. Ronald Kahn and colleagues identified 374 genes in total. The network includes newly identified genes important for kicking off the differentiation process, as well as those previously known to be involved in the final stages.

Necdin, one of the key factors identified in the study, is an inhibitor of the process and loss of its expression is essential for these fat cells to develop properly. In fact, forced loss of Necdin expression can re-activate the development process in prematurely blocked immature fat cells. Necdin is an entirely unknown player in the early stages of fat-cell differentiation and reveals a new area of investigation with potential therapeutic implications.